Purpose :
Intrastromal ring segments are known to reduce the magnitude of irregular astigmatism, but whether they allow freedom from use of medical contact lenses is less clear. We performed a retrospective chart review of patients with corneal ectasia to determine whether post-surgical contact lens modality was affected.

Methods :
58 eyes of 42 patients age 23 to 81 years (n=32 males and 24 females) with a diagnosis of keratoconus or LASIK induced corneal ectasia who were implanted with intrastromal ring segments in at least one eye over a 10 year period were included. Refraction, visual acuity, keratometry, apical thickness and elevation were measured with the Pentacam (Oculus) before and 6 months after surgery. The primary endpoint was type of contact lens fit at 6 months after surgery. Descriptive statistics were used for data analysis.

Results :
52 eyes carried a diagnosis of keratoconus and 6 eyes had LASIK induced ectasia. 90% of subjects in this review had Stage 4 disease. Patients using hybrid lenses: 12.5% were fit with custom soft lens, 18.75% were fit with a commodity soft lens, 18.75% stayed in a hybrid, 12.5% were fit with a scleral lens, 18.75% were without lenses. Patients using corneal rigid gas permeable lenses: 6.25% were fit with a custom soft lens, 18.75% were fit with commodity soft lenses, 18.75% went into a hybrid, 0% were fit in a scleral, 37.53% stayed in a rigid gas permeable lens, and 18.75% wore no lens. Patients who did not use lenses before the procedure (due to intolerance (72%) or inability to achieve a successful fit (28%): 25% were fit with rigid lenses post-operatively, 30% were fit in a scleral lens and 44% continued not to wear a lens.

Conclusions :
This review of patients with advanced corneal ectasia demonstrated that the majority of our patients enjoyed improvements in refractive and topographical parameters, but most still required the use of custom contact lenses. In our cohort, 11% of treated eyes were free of contact lenses, but 57% required the use of medical, custom contact lenses post-operatively. We recommend that future studies on intrastromal ring segments include use of medical contact lenses as an outcome measure. Patients with advanced corneal ectasias should be properly counseled regarding the likelihood of needing custom contact lenses after placement of intrastromal ring segments.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.